ericsopa wrote:A circle has 5 points (top, bottom, left, right, center)How do I snap to one of the four points on the perimeter of a circle?(It appears that snapping is only allowed to the center of a circle)

Hi ericsopa

You could either:

1. Use "reference" snap (keycode- SR) available from snap options (in Pro version 3 - not sure in Version 2 or community version?) - * make sure to select the correct snap mode you need after "reference" snap!

Or

2. Draw "temporary" lines (2 points - on new or same layer) from top to bottom and left to right on your circle, then you can use these points to "snap" to the intersections to do your work;
and finally delete temporary lines, hide/remove layer!